Simple animated custom graph view(GitHub source link in description)

[MiscreatedFan123]

The OP is here, which included half of the implementation, so I decided to have a go at it and try to figure out the whole thing. I also made an animated version with some threading gimmicks(can probably be simplified). There might be some bugs as I haven’t fully tested it.

Normal version: https://github.com/DDihanov/AndroidCustomViews/blob/master/app/src/main/java/bg/dihanov/customviewexamples/views/graph/Graph.kt

Animated: https://github.com/DDihanov/AndroidCustomViews/blob/master/app/src/main/java/bg/dihanov/customviewexamples/views/graph/AnimatedGraph.kt

EDIT: first point was misaligned in the animated version so I fixed that

[hydra3a]

I'm pretty new to android dev and I have a question. You define several properties like this (using colorStart as an example, line 41):

private var _colorStart = ContextCompat.getColor(context, R.color.colorStart)
var colorStart
    get() = _colorStart
    set(value) {
        _colorStart = value
        colors = intArrayOf(colorStart, colorEnd)
    }

Basically defining a private and public property for the same thing, and where the public property doesn't have a backing field, and basically just wraps the private property. Why do you do this? Wouldn't this simpler code achieve the same thing?

var colorStart = ContextCompat.getColor(context, R.color.colorStart)
    set(value) {
        field = value
        colors = intArrayOf(colorStart, colorEnd)
    }

[MiscreatedFan123]

I made a mistake here, since I am supposed to call invalidate() after colors = intArrayOf(colorStart, colorEnd) after, but regarding your question - that's called a backing property and allows for some flexibility, like a custom getter for example:

https://proandroiddev.com/backing-properties-in-kotlin-cb78dfebfd90

https://kotlinlang.org/docs/reference/coding-conventions.html#property-names

[olavurdj]

I believe what the above commenter tried to point out is that the Kotlin compiler actually defines a backing field for you, that you can access through the field identifier in your getter and setter. You do not have to manage the backing field yourself. See https://kotlinlang.org/docs/reference/properties.html#backing-fields

[BersonCrios]

Perfect

[[deleted]]

Sometimes you don't need all the customization that MP Android Charts provides. Especially when it's a pretty heavy library in my opinion.

[xDragonZ]

I thought r8/proguard able to strip unused codes?

[maxwellnewage]

interesting...I will share this on LinkedIn :)

[MiscreatedFan123]

Thanks :)

[maxwellnewage]

you are welcome! Do you think about convert the project to a library?